Francis w



(No Model.)

I. W. JONES.

TELEGRAPH TRANSMITTER.

No. 425,511. Patented Apr. 15,1890.

UNITED STATES PATENT OFFICE.

FRANCIS W. JONES, OF NElV YORK, N. Y.

TELEGRAPH-TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 425,511, dated April 15, 1890.

Application filed June 11, 1889. Serial No. 313,919. (No model.)

b aZZ whom it may concern.-

- State of New York, have invented a certain new and useful Telegraph Transmitter, of which the following is a specification.

My invention relates to telegraph-tramsmitters such as are used in duplex or quadruplex telegraphs, and which are provided with two contacts or circuit-closing points, one of which is closed when the transmitter is on its back stop and the other of which is closed when the transmitter is drawn against its front stop, the first-named contact being then opened. In this class of transmitters as ordinarily constructed it is usual to employ a spring-contact for the purpose of preserving the continuity of circuit-that is to say, preventing the opening of circuit at either point before circuit is closed at the other. This spring-contact as ordinarily employed opposes the movement of the transmitter-lever on its down or front stroke-that is to say, as it moves from its back to its front stopthereby interfering with its free movement and preventing the lever from striking its stop in a way to givea full or strong sound. As a consequence, the utility of the transmitter-lever as a sounderlever by which the Morse operator may read his own writing is impaired, the instrument giving a dull or weaker sound on the downstroke, when the sound, in order to correspond to the action of an ordinary sounder, should be comparatively full and strong.

The object of my invention is to avoid this defect in two-point continuity preserving transmitters and to permit the operator to read from the sounds given by his transmitter-lever with the same facility that he would from any ordinary sounder, to which end my invention consists in arranging the continu ity-preserving spring of a two-point transmitter so that it shall oppose the movement of the lever on the back or up stroke thereof, and not upon the downst'roke, leaving the lever free to strike its front stop with a heavy or full stroke on its down or front movement.

A further object of my invention is to avoid a practical defect which exists in the ordinary form of transmitters in which the contact- W spring used in connection with a fixed stop is carried by the vibrating lever, which is worked by a local electro-magnet and plays between suitable fixed stops. This defect alluded to arises from the fact that the sp ing, being attached to the lever, receives a jar when the lever strikes a fixed stop and is liable to vibrate and cause variation or interruption of circuit at the point where the spring makes contact with the lever by which it is carried. I avoid this difficulty by supporting such spring or yielding contact on an independent fixed support, and by causing the lever to im pinge upon it for the purpose of making and breaking circuit, instead of movin g the spring bodily.

In the accompanying drawings 1 have shown in Figure] in side elevation a two-point transmitter constructed in accordance with my i11- vention and connected to the receiving apparatus of an ordinary duplex telegraph. In Fig. 2 I have shown a double contact-trans mitter constructed in accordance with my invention and applied to a different arrangement of transmitting-circuits for the purpose of connecting sources of different polarity to the same line.

Referring to Fig. 1, A indicates the transmitter-lever, which, by playing between stops a I), gives a sound that enables the operator to read his own message. The lever A is operated by means of an electro-magnet 13, con trolled by a key and local circuit, as well understood in the art.

C is a contact lever or spring mounted on a suitable support independently of the lever A, as indicated, and arranged to be engaged by the conducting end D of said lever, so as to be removed from contact with a stop E. The part D of lever A being connected directly to ground and the stop E being connected to the battery M B or other source, it will be seen that the spring C performs the office of aback contact for the tranmitter and the stop E the office of' a front conducting-contact. It will also be seen, further, that as the lever A moves from the stop a toward. its front stop I) under the influence of the elcctro-magnet B, for the purpose of permitting connection of the spring with the stop E, so as to close the circuit of the battery M B, it will. move unimpeded by the action of the contact-spring C, and that the contact-spring 0 will only oppose the movement of said lever as it moves back toward the stop (4; hence on the front stroke of the lever it is permitted to give a full or loud sound. The impedimentfurnished by the spring 0 to the back movement tends to weaken the sound made by the lever in striking its back stop a, and therefore to still further accentuate the difference in sound between the front and back strokes, which so far from being a disadvantage is, in fact, an advantage. As a single transmitter for an ordinary duplex telegraph working by changes of tension the spring 0 is connected, as indicated, to the point X, Where the circuit divides into the main and artificial lines L L as well understood in the art.

In Fig. 2 I have illustrated the same construction applied to connecting in turn two sources of current M M of different polarity to the main line, thus producing in effect a change in the polarity of current circulating over such line. In this instance the apparatus is illustrated as in use with a polar duplex operating after the manner well understood in the art.

What I claim as my invention is- In a continuity-preservingtwo-point transmitter, the combination, substantially as described, of a contact-lever A, an electro-magnet B, arranged to act on the same, a yielding contact 0, supported independently of said lever on a fixed support and connected to the main line, a fixed contact or conducting stop vE, of one polarity with which said yielding 

